Virtual Reality (VR) is well-known to induce various physiological discomforts, ranging from mild headaches to the vomit reflex. It also well-known that the main cause of this is the mismatch between the visual system input and the vestibular system (sensed with the semicircular canals for rotational movements and otoliths for translational movements). For example, the visual field may say the body should be rotating, but the vestibular system says it is stationary. This conflict in expectations can lead to nausea. In more detail, the OKR (optokinetic reflex, due to visual field motion) and VOR (vestibular ocular reflex, due to head rotations), also may be in conflict. VOR and OKR share the same vestibular nuclear neurons and oculomotor neurons, and form a servo system to stabilize vision. The VOR/OKR pathways are intertwined through the corpus callosum to the vestibular nuclei, and have internuclear connections between motor nuclei and other connections with the cerebellum.
The symptoms of discomfort grow with increasing mismatch and duration, and begin with a twinge in the stomach or feelings of light-headedness. A speculation for this effect is that humans have evolved to assume that this mismatch is caused by consumed poisons interacting with the nervous system, and therefore the best reflex is to empty the stomach quickly, hopefully getting rid of poisons, at least the portions that have not already caused the mismatch. If the causes either persist or increase, the discomfort increases causing symptoms such as mild headaches. Further increases may cause nausea, vomiting or extreme long lasting headaches (which can last over 8 hours).
The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section. Similarly, issues identified with respect to one or more approaches should not assume to have been recognized in any prior art on the basis of this section, unless otherwise indicated.